
#PURPOSE: Simple program that exits and returns a
# status code back to the Linux kernel
#
#INPUT: none
#
#OUTPUT: returns a status code. This can be viewed
# by typing
#
# echo $?
#
# after running the program
#
#VARIABLES:
# %eax holds the system call number
# %ebx holds the return status
#
.section .data 
.section .text 
.globl _start
_start: movl $1, %eax # this is the linux kernel command 
                      # number (system call) for exiting 
                      # a program 
movl $4, %ebx         # this is the status number we will 
                      # return to the operating system. 
                      # Change this around and it will 
                      # return different things to 
                      # echo $? 
int $0x80             # this wakes up the kernel to run 
                      # the exit command
